Donald Trump has failed to deliver on his foundational campaign promise, his proposed absurd wall along the Mexican border. Even Republicans in Congress realize the wall would be a colossal waste of taxpayer dollars. Increasingly desperate to keep his xenophobic supporters placated, Trump’s announced that he is sending the National Guard to the border to keep out migrants.

If Trump ever does get his wall — a prospect that seems increasingly unlikely, especially given the fact that it looks like the Democrats are going to seize control of Congress in 2018 — it will be completely ineffective at curbing undocumented immigration.

Most undocumented immigrants get into the United States not by sneaking across the border, but by flying in on visas and staying beyond the expiration dates. Furthermore, walls can be scaled or dug under. The maintenance and defense of the wall would be a financial burden on Americans for decades to come.

Now, The Hillreports that Admiral Paul Zukunft, the Commandant of the U.S. Coast Guard is voicing his opinion on Trump’s ludicrous wall. Simply put, he doesn’t think it will work.

“I think we’d be shortsighted to think that if we build a wall that will end all the drivers for illegal migration,” said Zukunft to the Defense Writers Group in Washington.

“If you can’t come across a terrestrial border between Mexico and the United States, then go around it. “We keep a very close eye on what those trends are. Hasn’t happened, but that would probably be several years [away],” he added.

Zukunft is, of course, correct. A wall would have a negligible effect on immigration. People desperate to get into the United States in search of a better life would still be able to get into the country, whether by plane or, as Zukunft alludes to, by sea. Trump’s wall would not work, and any politicians who support it are either clueless or intentionally misleading the American people.